The formation of Fe colloids and layered double hydroxides as sequestration agents in the natural remediation of mine drainage
The formation of Fe colloids and layered double hydroxides as sequestration agents in the natural remediation of mine drainage
复制标题
DOI：
10.1016/j.scitotenv.2021.145183
复制
发表时间：
2021-02-19
影响因子：
9.8
通讯作者：
Sato, Tsutomu
中科院分区：
文献类型：
--
作者：
Chikanda, Frances;Otake, Tsubasa;Sato, Tsutomu
随着矿山废水处理需求的日益增长，被动处理系统引起了人们的关注。胶体在矿水中很常见，具有很强的反应性，因此为了设计有效的处理系统，需要了解它们的形成、特征、行为以及影响它们的关键因素。在2016年雨季和2018年旱季，对日本爱奈矿废弃排水系统进行曝气去除环中性污水中Fe、As和Zn的研究，并对其理化特征、溶解组分和胶体组分元素浓度、透射电镜和合成实验进行了观察。在这种环中性的富铁矿井水中，Fe2+被氧化成Fe3+，形成铁胶体，并在形成过程中结合As。胶体的形成增加了浊度，在雨季，增加的胶体相互作用增强了它们的聚集，更高的流速导致胶体的更大动员。在爱乃矿水系中，由于锌含量低，含锌胶体较为少见。通过地球化学模拟和实验，确定了锌铁层状双氢氧化物（LDH）的存在。在pH大于7.5的条件下，将Zn同构取代为Fe2+-Fe3+-CO32-LDH，形成Zn- fe LDH，实现了对排水中Zn和As的高效自然修复。(c) 2021提交人。这是一篇基于CC by许可（http://creativecommons.org/licenses/by/4.0/）的开放获取文章。
The increasing need to treat wastewater from mine effluents has drawn attention to passive treatment systems. Colloids are common in mine waters and are highly reactive, so their formation, characteristics, behavior, and the critical factors that affect them need to be understood for designing efficient treatment systems. An investigation was conducted at the abandoned Ainai mine drainage, Japan, where aeration is utilized to remove Fe, As, and Zn from circumneutral wastewater drainage, during rainy and dry seasons of 2016 and 2018 respectively, based on observations of physiochemical characteristics, elemental concentrations in dissolved and colloidal fractions, transmission electron microscopy, and synthetic experiments. In this circumneutral Fe-rich mine drainage, Fe2+ is oxidized to Fe3+, resulting in the formation of Fe colloids that incorporate As during their formation. Colloid formation increases turbidity, and, in the rainy season, increased colloidal interaction enhances their aggregation and higher flow rates lead to greater mobilization of the colloids. Zn-bearing colloids are rare in Ainai mine drain-age because the Zn concentrations are low. However, Zn-Fe layered double hydroxide (LDH) was identified and confirmed by geochemical modelling and experiments. The Zn-Fe LDH was formed by isomorphous substitution of Zn into an Fe2+-Fe3+-CO32-LDH, at pH greater than 7.5, thereby achieving efficient natural remediation of Zn and As in the drainage. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).